Balloon envelope fabric



epio 2% 1956 LEBIME HAL 2,523,312 I BALLOON ENVELOPE FABRIC Filed March7, 1941 I INVENTORS RENE LEBOIME as HENZZYACgEAU T \R ATTORNEY PatentedSept. 26, 1950 BALLOON ENVELOPE FABRIC Ren Leboime, Collonges, and HenriJacqueau,

Paris, France; vested in the Attorney General of the United StatesApplication March 7, 1941, Serial No. 382,146 In France May 28, 1940Sections 3 and 14, Public Law 690, August 8, 1946 Patent expires May 28,1960 The present invention relates to the manufacture of flexible piecesor walls which must have simultaneously, qualities of resistance againstfire, and some other qualities, such, for instance, as fluidtightnessagainst the passage of gases (and in particular hydrogen), mechanicalstrength, and so on. The invention is more especially, although notexclusively, concerned, among these articles, with flexible envelopes orreservoirs intended to contain a fluid, and in particular a gaseousfluid under pressure, and, more specifically, balloon envelopes.

The essential object of the present invention is to provide an articleof this kind which is bet ter adapted to meet the requirements ofpractice than those used for the same purpose up to this time.

According to an important feature of the present invention, in order toobtain a flexible article of the type above referred to, we haveessentially recourse, on the one hand, to a structure, such as a fabric,of asbestos or any other which is relatively flexible and isincombustible in itself, and, on the other hand, to means (such forinstance as another fabric, for instance of a textile material, eithercombustible or not) intended to give the desired various properties tothe whole; the combination thus obtained is such that, if the asbestosstructure happens to be bared by a local fire, it constitutes a kind ofscreen which tends to prevent the propagation of fire, while itmaintains, at the place where it has been injured, a certain mechanicalresistance, which prevents the tearing of the whole.

Another feature of the present invention relates to hollow bodies havinga flexible wall and which are liable to be endangered by fire. such, inparticular, as balloon envelopes. It consists in reinforcing theresistance of said flexible wall at the lower part of the body, that isto say in the portion thereof where the propagation of fire is to bemost feared, due to the fact that the flames escaping from the injuredbody have a tendency to curve back upwardly toward the wall thereof.

Other features of the present invention will result from the followingdetailed description of some specific embodiments thereof.

Preferred embodiments of the present invention will be hereinafterdescribed, with reference to the accompanying drawings, given merely byway of example, and in which:

Fig. 1 is a diagrammatic cross-sectional View of a composite fabricadapted to be used as a balloon envelope, illustrating what takes placewhen a hole has been made in said envelope and 4 Claims. (01. 154-46) 2ignited gas is escaping through said .hole the inside of the balloon;

Fig. 2 is a partial plan view corresponding to Fig. 1.

In the following description, it will be supposed that the invention isapplied to the manufrom facture of a fabric intended to be used forconof a balloon intended to be inflated with an inflammable gas.

First, it should be noted that various methods have already beensuggested for endeavouring to give a fabric to be used for this purpose,in addition to the different propertie corresponding to its function(which is to constitute, under a relatively small weight, a gas-tightenvelope), as good a resistance to fire as possible.

It seems that this fabric should comply with all Of the followingconditions, to wit:

a. Resistance to fire, that is to say at least resistance to the quickpropagation of fire, after ignition of the gas escaping through a holemade in the envelope; r

b. Mechanical resistance, that is to say the fact of maintaining asuitable resistance, after perforation and inflammation of the envelope,in order to avoid the tearing off thereof and the consequent explosion;

c. Fluidtightness against gases, and especially hydrogen;

d. Relatively small weight;

Then, accessorily:

e. Sufficient flexibility, in order to permit all deformations; and

f. A good aging, that is to say, in particular, a suitable resistance tothe action of sun rays and external agents.

As a matter of fact, the essential object of the present invention is toprovide a structure which complies with all of these conditions.

It has already been suggested to constitute it by means of fabricsconsisting chiefly of matters such as asbestos.

Now, after many experiments, we have found that it is possible to make,for the purpose above indicated, a material including asbestos which,

although it comprises matters which are relatively combustible, makes itpossible to resist the action of fire, asbestos having this unexpectedeffect of delaying the propagation of fire.

This phenomenon, on which the principle of the present invention isbased, seems to be ex plainable in the following manner: Considering anenvelope made of a structure, for'instance a fabric including anasbestos texture, and supposing that the ignited gas is in the form of ajet l issuing from a hole (1 (Figs. 1 and 2), ignition of thecombustible matters included in said fabric is delayed'by theifact thatasbestos, bared as the combustion proceeds in a zone such as 1), acts asa kind of metallic wire net tending to delay the propagation of fire.

Furthermore, this asbestos, during and after combustion, constitutes aresistant support which prevents tearing.

Therefore, the envelope or the like, according to the present invention,includes the following elements:

a. On the one hand, a layer of a matter which is not combustible,preferably asbestos as'it will be supposed in the following description;however, it should be well understood that any other incombustiblematter, either mineral or not (such, for instance, as slag wool, glasssilk, and so on) might be used, either-alone or in combination withasbestos; and

b. On the other hand, "means combined'with ithis'layer and adapted togive the whole the'various conditions required from such an article; thechoiceand'adaptation of these last mentioned means :becoming'relativelyeasy, in view of the fact that'their eventual combustion is in no way a"serious'obstacle.

. r..IThis=principle maybe applied in many different manners, and inparticular as follows:

t.Concerning first the part of the structure which -.is madebf-a'sbestosor another equivalent material "such as above mentioned, it ispreferably made in the form of at least one sheet of a fabric -A-(Figs/land 2) which is to be both light and strong, .thereforerelatively closely-woven, the spaces between the warp and weft-threadsbeing as reduced as possible.

For instance the. threadswill be of a thickness corresponding to 10,000to 20,000 meters perkilogram, fth'eirnumber ranging from 8 to 20 percentimeter; but itshould be Well understood that these values are givenmerely by way of indicationand'have'no limitative character.According-to an embodiment of our invention, the thickness-'of' thefabric ranges from to /10 of a m'illim'eter.

The above mentioned elements and principle produce a fabric havingvarious properties that the asbestos fabric does not have when takenalone. The fabric is preferably made as follows:

:a. Either merely by means of one or several coatings capable, inparticular, of making the layer or layers of asbestos or asbestos fabricgastight; 1 f Z). Or, preferably, by means of at least one other fabricB, forming at least one layer, and preferably combined with one orseveral coatings.

Considering the case of the second mentioned means, andconcerning'firstthe choice of'this fabricB,'- we' may make use of a fabric of a vegetal,animal, or other type, for instance made of cotton, wool, silk,artificial silk and so on. But ltTSh0lI1d"-be well understood that we donot exclude fabrics made of incornbustible materials (such asasbestos,glass silk, a metal net, and-so onrandwthat this'second fabric B mighteven be identicahwith the first fabric A.

The-second fabric will be preferably woven very close,5andwithtightly'juxtaposed threads, so as to ensure as good a fluidtightness asit is possible.

Concerning the choice of the coating or coatings, it'rnay beadvantageous to make use of mixtures containing plastic materials, such7 as those 4 known in the rubber industry and, in particular, in themanufacture of rubberized fabrics.

However, it seems preferable to make use of coatings consistingchieflyofsynthetic rubber, whichhas very valuable properties of aging(non-alteration by sun rays) Preferably, we make use of a syntheticrubber consisting chiefly of neoprene.

Now, having, for instance, at least two layers of fabric, which may beconstituted, as above stated, either by the same material, or rather, asit will be hereinafter supposed, by two different materials A and B, weproceed, for instance, for the incorporation of the coating or coatings,in one of the following manners:

First, such a coating is advantageously used for causing the two fabricsA and B to adhere to each other at 2 (Fig. 1), this result beingobtained in any manner known in the manufacture of rubberized fabrics.

Furthermore, the composite fabric thus obtained is provided, either onone of its external faces oronboth of these faces, as shown at 3 and '4in Fig. 1, with'one or severa1 layers of this coating this operationbeing effected in'any suitable manner, for instance by impregnation onthe loom or by calendering.

These layers maybe all of'the same'thickness or onthecontrary "ofdifferent respective thick- 'nesses; the wholebeing'such that the totalthickness of the fabric obtained remains sufficiently small formaintaining the desired qualities of flexibility and light wei ht, sucha thickness ranging preferably from /10 to /10 or even /10 ofmillimeter.

These layers serve chiefly to ensure fluidti'ghtness and good ageingqualities (resistance to 'the ac'tion' of the sun rays and of externalagents) owing to the very nature of these coatings.

Furthermore, they have a relatively considerable resistance to theaction of fire, it being Well understood however that, inany case,asbestos is brought into play for'delaying the-action of fire on theadjoining surfaces, in the conditions above stated, and also forensuring-a goodmechanical resistance.

Eventually, the whole might be completed, on the outer side, by afluidtight varnish impervious to gases andresisting the action'of--atmospheric agents. This varnishmight be superposed to one of thelayers 3 and 4; and it might even wholly replace it. I

Finally, it should-be noted that, to at least some of the variousconstitutive elements above-specified (fabrics, coatings, varnishes) wemay eventually adjoin fire-proofing products. 'By'way of example, theseproducts might consist -at least partly ofannnoniaco-ma'gnesiumphosphates, of boron-phosphates of-ammonium, and so on.

Whatever be the particular'embodiment that is chosen, we obtain'fabri'cswhich ='are well' 'a'dapted tobe used forthe purposes "abovementioned and comply with many combined'conditions, the" chief of whichare the following:

Resistance tofirefiowing to the special action of asbestos, which-delaysthe propagationof firei :Mechanical resistance, asbestos also having,from this point of'view, the 'property'of opposing tearing off after alocalfir'e;

Gas tightness;

Light weight; "Flexibilit'w and I -Re'sistance' to theactionof-atmospheric agents.

Of course, the application of our invention to the manufacture ofenvelopes for balloons has no limitative character.

For instance, the invention might be also applied, among other uses;

a. To the construction of flexible tanks or reservoirs adapted tocontain liquids or gases, either inflammable or not b. To themanufacture of fabrics for home decoration (curtains, wall coverings andso on), for clothes of all kinds, etc.

0. To the construction or external covering of pipes, either flexible ornot, for liquids or gases, etc.

When the invention is applied to the construction of balloons, anotherfeature of our invention consists in reinforcing the qualities ofresistance to the action of fire of the envelope in the lower portion ofsaid balloons.

In this portion of the balloon, the jet of ignited gas issuing from ahole made in the envelope, as illustrated at I in Fig. 1, is, at itsbase directed downwardly. But as the gas is lighter than air, this jettends to curve upwardly and to come into contact with surroundingportions of the envelope, which increases the damage caused by theflames.

In order to improve the resistance of this lower 7 portion of theballoon, we may proceed in any suitable manner, acting for instance onat least one of the following characteristics, to wit: number of layersof fabric, thickness of these layers, thickness of the coatings,addition of fire-proofing products, etc.

The above description and specific examples are to be taken asillustrative only. ()ther practical and efficient embodiments such aschanges in the arrangement, disposition and form of the parts may bemade by those skilled in the art without departing from the nature andscope of the invention as defined in the appended claims.

What we claim is:

1. A balloon envelope fabric impermeable to gases and possessing theproperties of flexibility and fire-resistance which comprises an outerlayer of flexible woven mineral fabric, an inner layer of a flexiblewoven organic textile fabric and a coating of plastic material onsaidsecond mentioned layer to make it impervious to gases, the secondmentioned layer being united to and in contact with the first mentionedlayer over the whole of the contiguous surfaces of these two layers.

2. A balloon envelope fabric impermeable to gases and possessing theproperties of flexibility and fire-resistance which comprises an outerlayer of flexible woven asbestos fabric, an inner layer of a flexiblewoven organic textile fabric and a coating of plastic material on saidsecond mentioned layer to make it impervious to gases, the secondmentioned layer being united to and in contact with the first mentionedlayer over the whole of the contiguous surfaces of these two layers.

3. A balloon envelope according to claim 1, in which said coating ismade chiefly of synthetic rubber.

4. A balloon envelope according to claim 1, in which said coating ismade chiefly of neoprene.

R. LEBOIME. HENRI JACQUEAU.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 737,751 Lougee Sept. 1, 1903885,376 Ray Apr. 21, 1908 1,081,794 Vaniman Dec. 16, 1913 1,245,196Crawford Nov. 6, 1917 1,427,708 Williams Aug. 29, 1922 1,519,239 ClayDec. 16, 1924 1,730,763 Gerding Oct. 8, 1929 1,788,394 Jacobsohn et alJan. 13, 1931 1,967,863 Collins et a1. July 24, 1934 2,126,818 SagerAug. 16, 1938 FOREIGN PATENTS Number Country Date 4,098 Great Britain1882

1. A BALLOON ENVELOPE FABRIC IMPERMEABLE TO GASES AND POSSESSING THEPROPERTIES OF FLEXIBILITY AND FIRE-RESISTANCE WHICH COMPRISES AN OUTERLAYER OF FLEXIBLE WOVEN MINERAL FABRIC, AN INNER LAYER OF A FLEXIBLEWOVEN ORGANIC TEXTILE FABRIC AND A COATING OF PLASTIC MATERIAL ON SAIDSECOND MENTIONED LAYER TO MAKE IT IMPERVIOUS TO GASES, THE SECONDMENTIONED LAYER BEING UNITED TO AND IN CONTACT WITH THE FIRST MENTIONEDLAYER OVER THE WHOLE OF THE CONTIGUOUS SURFACES OF THESE TWO LAYERS.